Sole and shoe

ABSTRACT

A sole includes a midsole, a bottom plate, a top plate, and at least one pin retaining member. The bottom plate includes a plate body having a reference surface and at least one base portion. The bottom plate includes a thenar region corresponding to an area located between a first portion and a second portion to support a big toe of a foot. The first portion corresponds to 20% of a total length of the sole from an MP overlapping portion toward a front side, and the second portion corresponds to 20% of the total length of the sole from the MP overlapping portion toward a rear side. The at least one base portion includes a thenar base portion disposed in the thenar region. A lower surface of the thenar base portion is formed to be flush with the reference surface or recessed above the reference surface.

CROSS REFERENCE TO RELATED APPLICATIONS

This nonprovisional application is based on Japanese Patent Application No. 2022-124010 filed on Aug. 3, 2022 with the Japan Patent Office, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to a sole and a shoe.

Description of the Background Art

Japanese Patent Laying-Open No. 2001-340101 discloses a hard shoe sole of a spike shoe for track and field athletics, including: a plate-shaped shoe sole body portion that supports a bottom surface of a foot; and a plurality of spike mounting portions formed on a rear surface of the shoe sole body portion. A metal spike is fixed to each of the spike mounting portions. The plurality of spike mounting portions include a first spike mounting portion provided at a position corresponding to the first metatarsophalangeal joint. Each spike mounting portion protrudes from the rear surface of the shoe sole body portion.

SUMMARY OF THE INVENTION

It is desirable that the hard shoe sole of the spike shoe for track and field athletics as disclosed in Japanese Patent Laying-Open No. 2001-340101 be enhanced in stability of the motion of a foot during a period from when the foot contacts the ground to when the foot takes off from the ground.

It is an object of the present disclosure to provide a sole and a shoe capable of enhancing the stability of motion of a foot during a period from when the foot contacts the ground to when the foot takes off from the ground.

A sole according to one aspect of the present disclosure is a sole forming a part of a shoe, the sole including: a midsole; a bottom plate connected to a lower surface of the midsole; a top plate connected to an upper surface of the midsole; and at least one pin retaining member that is configured to retain a spike pin. The bottom plate includes: a plate body having a reference surface; and at least one base portion that holds the at least one pin retaining member. The bottom plate includes a thenar region corresponding to an area located between a first portion and a second portion to support a big toe of a foot of a wearer of the shoe, the first portion corresponds to 20% of a total length of the sole extending toward a front side in a foot length direction of the sole from an MP overlapping portion that overlaps with an MP joint of the foot of the wearer in a thickness direction of the sole, and the second portion corresponds to 20% of the total length of the sole extending toward a rear side in the foot length direction from the NIP overlapping portion The at least one base portion includes a thenar base portion disposed in the thenar region. A lower surface of the thenar base portion is formed to be flush with the reference surface or to be recessed above the reference surface.

A shoe according to one aspect of the present disclosure includes: the sole; and an upper connected to the sole and forming, together with the sole, a space in which the foot of the wearer is received.

The foregoing and other objects, features, aspects, and advantages of the present invention will become apparent from the following detailed description of the present invention, which is understood in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view schematically showing a shoe according to a first embodiment of the present disclosure.

FIG. 2 is a plan view of a sole.

FIG. 3 is a bottom view of the sole.

FIG. 4 is a cross-sectional view taken along a line IV-IV in FIG. 3 .

FIG. 5 is a cross-sectional view taken along a line V-V in FIG. 3 .

FIG. 6 is a cross-sectional view taken along a line VI-VI in FIG. 3 .

FIG. 7 is a cross-sectional view taken along a line VII-VII in FIG. 3 .

FIG. 8 is a bottom view of a sole of a shoe according to a second embodiment of the present disclosure.

FIG. 9 is a cross-sectional view taken along a line IX-IX in FIG. 8 .

FIG. 10 is a cross-sectional view schematically showing a shoe according to a third embodiment of the present disclosure.

FIG. 11 is a bottom view of a sole.

FIG. 12 is a cross-sectional view taken along a line XII-XII in FIG. 11 .

FIG. 13 is a cross-sectional view taken along a line XIII-XIII in FIG. 11 .

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be hereinafter described with reference to the accompanying drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals. In the following description, terms such as a foot length direction, a foot width direction, forward, rearward are used. Each of these terms representing directions indicates the direction as seen from a viewpoint of a wearer of a shoe 1 placed on a flat plane P (see FIG. 1 ) such as the ground. For example, forward refers to the side toward a toe and rearward refers to the side toward a heel. Further, the inner side or the medial foot side refers to the first-toe (big toe) side of the foot in the foot width direction, and the outer side or the lateral foot side refers to the fifth-toe side of the foot in the foot width direction.

First Embodiment

FIG. 1 is a cross-sectional view schematically showing a shoe according to the first embodiment of the present disclosure. FIG. 2 is a plan view of a sole. FIG. 3 is a bottom view of the sole. While FIGS. 2 and 3 each show a sole 10 for a left foot, this sole 10 is also applicable to a right foot. In this case, the sole for a right foot is formed in a shape in bilateral symmetry with the sole for a left foot, or in a shape nearly identical thereto. The shoe 1 of the present embodiment is suitable for use as a spike shoe provided with spike pins, in particular, as a spike shoe for track and field athletics. The use of the shoe 1, however, is not limited thereto but is applicable also to spike shoes for ball games such as baseball and football.

As shown in FIG. 1 , the shoe 1 includes the sole 10 and an upper 20.

The upper 20 is connected to the sole 10. The upper 20 and the sole 10 together form a space in which a foot of a wearer is received. The upper 20 covers the upper surface of the foot of the wearer.

The sole 10 forms a part of the shoe 1. The sole 10 is connected to a lower part of the upper 20. As shown in FIGS. 1 and 3 , the sole 10 includes a midsole 100, a bottom plate 200, a top plate 300, a midsole top 400, an outsole 500, and at least one pin retaining member 600.

The midsole 100 has; a shock absorbing function exerted when a foot contacts the ground; a resilient function exerted when a foot takes off from the ground; and the like. The midsole 100 is preferably made of foamed resin or foamed rubber having appropriate strength and excellent shock absorbing performance. As shown in FIG. 1 , the midsole 100 includes a forefoot midsole 110 and a rearfoot midsole 120.

The forefoot midsole 110 supports a forefoot portion or a midfoot portion of the wearer's foot. The forefoot midsole 110 is formed, for example, by physical foaming of a resilient material (nylon and the like).

The rearfoot midsole 120 supports a rearfoot portion of the wearer's foot. The rearfoot midsole 120 has a shape extending rearward from a rear end portion of the forefoot midsole 110. The rearfoot midsole 120 is formed, for example, of a resin-made foam material containing: a resin material as a main component; and a foaming agent and a cross-linking agent as sub-components. The rearfoot midsole 120 is formed, for example, by chemical foaming of ethylene-vinyl acetate (EVA).

The bottom plate 200 is connected to a lower surface of the midsole 100. The bottom plate 200 is made of a thermoplastic resin or the like. The bottom plate 200 is higher in hardness than the midsole 100. The bottom plate 200 includes a plate body 210, at least one base portion 220, and a reinforcing portion 230.

The plate body 210 has a shape extending rearward from the front end of the midsole 100. Specifically, the plate body 210 extends from the front end of the forefoot midsole 110 to a position beyond the boundary between the forefoot midsole 110 and the rearfoot midsole 120. The plate body 210 has a reference surface 210S. The reference surface 210S means a lower surface of a surface connecting the thickest portions of the plate body 210. Note that FIGS. 4 and 5 each show the reference surface 210S by a two-dot chain line.

The base portion 220 holds the pin retaining member 600. The base portion 220 has a shape surrounding the pin retaining member 600.

In the present embodiment, the at least one base portion 220 includes a plurality of base portions 220. As shown in FIGS. 2 and 3 , the plurality of base portions 220 include two thenar base portions 221, two lateral foot-side base portions 222, and two toe base portions 223.

Each of the thenar base portions 221 is disposed in a thenar region R1. As shown in FIG. 2 , the thenar region R1 corresponds to an area located between a first portion L1 and a second portion 12 to support a big toe of the wearer's foot. The first portion L1 corresponds to 20%, more preferably 15%, of the total length of the sole 10 from an MP overlapping portion toward the front side in the foot length direction (in an up-down direction in FIG. 2 ) of the sole 10, and the second portion L2 corresponds to 20%, more preferably 15%, of the total length of the sole 10 from the MP overlapping portion toward the rear side in the foot length direction. The MP overlapping portion is a portion of the bottom plate 200 that overlaps with an MP joint (see FIG. 2 ) of the foot of the wearer of the shoe 1 in the thickness direction of the sole 10. In FIGS. 2 and 3 , the thenar region R1 is represented by diagonal lines.

The foot length direction extends in a direction parallel to a shoe center SC (see FIGS. 2 and 3 ). The shoe center SC is not limited to the centerline of the shoe 1 but may be a line corresponding to a straight line connecting the center of the calcaneus bone of a standard wearer of the shoe 1 and a point between the first toe and the second toe. FIG. 2 shows a heel center HC (a straight line connecting the center of the calcaneus bone of the standard wearer of the shoe 1 and a point in the vicinity of the fourth toe).

FIG. 1 shows a cross section of the shoe 1 taken along a line segment AB, a curved line BC, a line segment CD, and a line segment DE shown in FIG. 2 . A point A is a point of intersection between the shoe center SC and the front end of the sole 10. A point B is a point of intersection between the second middle phalanx and the shoe center SC. A point C is a point of intersection between the rear portion of the fourth metatarsal bone and the heel center HC. A point D is a point of intersection between the heel center HC and the shoe center SC. A point E is a point of intersection between the shoe center SC and the rear end of the sole 10.

In the present embodiment, one of the thenar base portions 221 (which may be hereinafter also referred to as a “thenar base portion 221A”) is disposed between the MP overlapping portion and the first portion L1, and the other of the thenar base portions 221 (which may be hereinafter also referred to as a “thenar base portion 221B”) is disposed between the MP overlapping portion and the second portion L2.

As shown in FIG. 4 , a lower surface 221S of the thenar base portion 221A disposed between the MP overlapping portion and the first portion L1 is formed to be recessed above the reference surface 210S of the plate body 210. A plurality of concave portions 211 recessed above the reference surface 210S are provided in a portion of the plate body 210 around the thenar base portion 221A. A portion provided with the concave portion 211 in the plate body 210 is formed to have a thickness t1 (see FIG. 4 ) of about 1.0 mm to 2.0 mm. A thickness t2 (see FIG. 4 ) of the base portion 220 is larger than the thickness t1 of the above-mentioned portion of the plate body 210. The thickness t2 of the base portion 220 is set at about 3.0 mm to 4.0 mm.

As shown in FIG. 5 , the lower surface 221S of the thenar base portion 221B disposed between the MP overlapping portion and the second portion L2 is formed to be flush with the reference surface 210S of the plate body 210. However, the lower surface 221S of the thenar base portion 221B may be formed to be recessed above the reference surface 210S of the plate body 210. A plurality of concave portions 212 recessed above the reference surface 210S are provided in a portion of the plate body 210 around the thenar base portion 221B. The depth of the concave portion 212 recessed from the reference surface 210S is smaller than the depth of the concave portion 211 recessed from the reference surface 210S and is set at about 0.3 mm.

Each of the lateral foot-side base portions 222 is disposed in a lateral foot-side region R2. As shown in FIG. 2 , the lateral foot-side region R2 corresponds to an area located between the first portion L1 and the second portion L2 to support a little toe of the wearer's foot. In FIGS. 2 and 3 , the lateral foot-side region R2 is represented by diagonal lines.

In the present embodiment, one of the lateral foot-side base portions 222 is disposed between the MP overlapping portion and the first portion L1, and the other of the lateral foot-side base portions 222 is disposed between the MP overlapping portion and the second portion L2.

The lower surface of the lateral foot-side base portion 222 disposed between the NIP overlapping portion and the first portion L1 is formed to be flush with the reference surface 210S of the plate body 210 or to be recessed above the reference surface 210S. A plurality of concave portions 211 and a plurality of concave portions 212 may be provided in an area of the plate body 210 around this lateral foot-side base portion 222.

The lower surface of the lateral foot-side base portion 222 disposed between the MP overlapping portion and the second portion L2 is formed to be flush with the reference surface 210S of the plate body 210. A plurality of concave portions 212 are provided in an area of the plate body 210 around the lateral foot-side base portion 222.

Each of the toe base portions 223 is disposed in a toe region R3. As shown in FIG. 2 , the toe region R3 corresponds to an area located in a forward portion of the first portion L1 in the foot length direction to support the toe of the wearer's foot in the thickness direction. In FIGS. 2 and 3 , the toe region R3 is represented by diagonal lines.

In the present embodiment, one of the toe base portions 223 is disposed on the inner side of the shoe center SC in the foot width direction (in the left-right direction in FIGS. 2 and 3 ) while the other of the toe base portions 223 is disposed on the outer side of the shoe center SC in the foot width direction.

As shown in FIG. 6 , a lower surface 223S of the toe base portion 223 disposed on the inner side of the shoe center SC in the foot width direction protrudes downward from the reference surface 210S of the plate body 210. A lower surface 223S of the toe base portion 223 disposed on the outer side of the shoe center SC in the foot width direction also protrudes downward from the reference surface 210S of the plate body 210.

The forefoot midsole 110 includes a receiving portion 112 (see FIGS. 4 to 6 ) recessed upward to receive each of the base portions 220. A portion of the forefoot midsole 110 that overlaps with the base portion 220 has a thickness that is equal to or more than 0.9 times and equal to or less than 2.3 times greater than a thickness t2 of the base portion 220.

The reinforcing portion 230 reinforces the plate body 210. As shown in FIGS. 2 and 3 , the reinforcing portion 230 is provided in a portion of the plate body 210 in the vicinity of the arch of the wearer's foot. As shown in FIG. 7 , the reinforcing portion 230 is formed of a plurality of ribs arranged side by side in the foot width direction (in the left-right direction in FIG. 7 ). Each of the ribs has a shape extending in the foot length direction.

The top plate 300 is connected to an upper surface of the midsole 100. The top plate 300 has a function of increasing the flexural rigidity of the sole 10, a function of uniformly applying a load to the midsole 100, and the like. The top plate 300 is made of a fiber reinforced resin or a non-fiber reinforced resin. In the present embodiment, the top plate 300 is made of a carbon fiber reinforced resin. The top plate 300 is formed to have a thickness of about 1.0 mm to 2.0 mm.

As shown in FIGS. 1 and 2 , the top plate 300 has a shape extending in the foot length direction so as to extend from a region supporting the wearer's toe in the thickness direction of the sole 10 to a region supporting the calcaneus bone of the wearer in the same thickness direction. In the top plate 300, a portion located forward of the portion corresponding to the MP overlapping portion has a shape curved to protrude downward and has a radius of curvature that gradually changes. Thereby, gradually changing resilient force is obtained. In the top plate 300, a portion located rearward of the portion corresponding to the MP overlapping portion has a shape curved to protrude upward. Thereby, the midfoot portion is effectively supported by the top plate 300 when the wearer's foot takes off from the ground.

The midsole top 400 is connected to an upper surface of the top plate 300. The midsole top 400 is formed, for example, by chemical foaming of EVA. As shown in FIG. 2 , the front end portion of the midsole top 400 is located at the same position as the front end portion of the top plate 300. The rear end portion of the midsole top 400 is located at the same position as the rear end portion of the rearfoot midsole 120. The midsole top 400 is formed to have a thickness of about 1.5 mm.

The outsole 500 is connected to a lower surface of the rearfoot midsole 120. The outsole 500 is made of rubber or the like. The outsole 500 is formed to have a thickness of about 2.0 mm to 3.0 mm.

The pin retaining member 600 serves to retain a spike pin (not shown). The pin retaining member 600 is capable of detachably retaining the spike pin. This makes it possible to replace the spike pin according to the purpose of use and the wear conditions of the pin. The pin retaining member 600 is formed of a nut. In the present embodiment, at least one pin retaining member 600 includes a plurality of pin retaining members 600. Specifically, the plurality of pin retaining members 600 include six pin retaining members 600 disposed on the respective base portions 220. The spike pin is not limited to a detachable type but may be a fixed type.

As described above, in the sole 10 according to the present embodiment, the lower surface 221S of the thenar base portion 221 is formed to be flush with the reference surface 210S of the plate body 210 or to be recessed above the reference surface 210S, which therefore enhances the stability of the motion of the foot during a period from when the foot contacts the ground to when the foot takes off from the ground.

Further, the plate body 210 is smaller in thickness than the base portion 220 and the midsole 100 has the receiving portion 112 in which the thenar base portion 221 is received. Thus, in the midsole 100, the thickness of the portion not overlapping with the thenar base portion 221 is ensured to a considerable degree while avoiding an increase in the sum of the thicknesses of the midsole 100 and the bottom plate 200. Therefore, the shock absorbing performance is enhanced.

Second Embodiment

The following describes a sole 10 of a shoe 1 according to the second embodiment of the present disclosure with reference to FIGS. 8 and 9 . In the second embodiment, only differences from the first embodiment will be described, but the same structures, functions, and effects as those in the first embodiment will not be described.

In the present embodiment, the plate body 210 is provided with neither concave portion 211 nor concave portion 212. As shown in FIG. 9 , the lower surface 221S of the thenar base portion 221 is formed to be flush with the reference surface 210S of the plate body 210. This also applies to each of the lower surfaces 220S of the other base portions 220. A thickness t1 of the plate body 210 in the present embodiment is the same as the thickness t1 of the portion provided with the concave portion 211 in the plate body 210 in the first embodiment.

Third Embodiment

The following describes a sole 10 of a shoe 1 according to the third embodiment of the present disclosure with reference to FIGS. 10 to 13 . In the third embodiment, only differences from the first embodiment will be described, but the same structures, functions, and effects as those in the first embodiment will not be described.

In the present embodiment, as shown in FIG. 11 , a plurality of base portions 220 include one thenar base portion 221, two lateral foot-side base portions 222, and one toe base portion 223. A pin retaining member 600 is disposed on each of the base portions 220.

Similarly to the second embodiment, the plate body 210 is provided with neither concave portion 211 nor concave portion 212. As shown in FIG. 12 , a lower surface 221S of the thenar base portion 221 and a lower surface 222S of each of the lateral foot-side base portions 222 are formed to be flush with the reference surface 210S of the plate body 210. This also applies to each of lower surfaces 220S of the other base portions 220.

As shown in FIGS. 11 and 13 , a plurality of ribs constituting the reinforcing portion 230 are shorter in length in the foot width direction than those in the first embodiment.

It will be appreciated by those skilled in the art that the above-described illustrative embodiments are specific examples of the aspects as set forth below.

-   -   [Aspect 1]

A sole forming a part of a shoe, the sole comprising:

-   -   a midsole;     -   a bottom plate connected to a lower surface of the midsole;     -   a top plate connected to an upper surface of the midsole; and     -   at least one pin retaining member that is configured to retain a         spike pin,         wherein     -   the bottom plate includes         -   a plate body having a reference surface, and         -   at least one base portion that holds the at least one pin             retaining member,     -   the bottom plate includes a thenar region corresponding to an         area located between a first portion and a second portion to         support a big toe of a foot of a wearer of the shoe, the first         portion corresponds to 20% of a total length of the sole         extending toward a front side in a foot length direction of the         sole from an MP overlapping portion that overlaps with an MP         joint of the foot of the wearer in a thickness direction of the         sole, and the second portion corresponds to 20% of the total         length of the sole extending toward a rear side in the foot         length direction from the MP overlapping portion,     -   the at least one base portion includes a thenar base portion         disposed in the thenar region, and     -   a lower surface of the thenar base portion is formed to be flush         with the reference surface or to be recessed above the reference         surface.

In the above-described sole, the lower surface of the thenar base portion is formed to be flush with the reference surface of the bottom plate or to be recessed above the reference surface, which therefore enhances the stability of the motion of the foot during a period from when the foot contacts the ground to when the foot takes off from the ground.

-   -   [Aspect 2]

The sole according to aspect 1, wherein

-   -   the bottom plate includes a toe region located in a forward         portion of the first portion in the foot length direction to         support a toe of the foot of the wearer in the thickness         direction,     -   the at least one pin retaining member includes a plurality of         pin retaining members, and     -   the at least one base portion includes a toe base portion         disposed in the toe region.

The above-described aspect makes it possible to exert sufficient grip force when the foot takes off from the ground.

-   -   [Aspect 3]

The sole according to aspect 2, wherein

-   -   the bottom plate includes a lateral foot-side region         corresponding to an area located between the first portion and         the second portion to support a little toe of the foot of the         wearer, and     -   the at least one base portion includes a lateral foot-side base         portion disposed in the lateral foot-side region.

The above-described aspect makes it possible to achieve both the sufficient grip force and the stability during a period from when the foot contacts the ground to when the foot takes off from the ground.

-   -   [Aspect 4]

The sole according to aspect 2 or 3, wherein a lower surface of the toe base portion protrudes downward from the reference surface.

The above-described aspect makes it possible to prevent the pin retaining member from pushing the wearer's foot upward at a portion where the midsole is reduced in thickness for the purpose of further enhancing the stability when the foot takes off from the ground.

-   -   [Aspect 5]

The sole according to aspect 3, wherein a lower surface of the toe base portion and a lower surface of the lateral foot-side base portion are formed to be flush with the reference surface.

The above-described aspect further enhances the stability of the motion of the foot during a period from when the foot contacts the ground to when the foot takes off from the ground.

-   -   [Aspect 6]

The sole according to any one of aspects 1 to 5, wherein the at least one pin retaining member is capable of detachably retaining the spike pin.

The above-described aspect makes it possible to replace the spike pin according to the purpose of use and the wear conditions of the spike pin.

-   -   [Aspect 7]

A shoe comprising:

-   -   the sole according to any one of aspects 1 to 6; and     -   an upper connected to the sole and forming, together with the         sole, a space in which the foot of the wearer is received.

Although the embodiments of the present invention have been described, it should be understood that the embodiments disclosed herein are illustrative and not restrictive in every respect. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the meaning and scope equivalent to the terms of the claims. 

What is claimed is:
 1. A sole forming a part of a shoe, the sole comprising: a midsole; a bottom plate connected to a lower surface of the midsole; a top plate connected to an upper surface of the midsole; and at least one pin retaining member that is configured to retain a spike pin, wherein the bottom plate includes a plate body having a reference surface, and at least one base portion that holds the at least one pin retaining member, the bottom plate includes a thenar region corresponding to an area located between a first portion and a second portion to support a big toe of a foot of a wearer of the shoe, the first portion corresponds to 20% of a total length of the sole extending toward a front side in a foot length direction of the sole from an MP overlapping portion that overlaps with an MP joint of the foot of the wearer in a thickness direction of the sole, and the second portion corresponds to 20% of the total length of the sole extending toward a rear side in the foot length direction from the MP overlapping portion, the at least one base portion includes a thenar base portion disposed in the thenar region, and a lower surface of the thenar base portion is formed to be flush with the reference surface or to be recessed above the reference surface.
 2. The sole according to claim 1, wherein the bottom plate includes a toe region located in a forward portion of the first portion in the foot length direction to support a toe of the foot of the wearer in the thickness direction, the at least one pin retaining member includes a plurality of pin retaining members, and the at least one base portion includes a toe base portion disposed in the toe region.
 3. The sole according to claim 2, wherein the bottom plate includes a lateral foot-side region corresponding to an area located between the first portion and the second portion to support a little toe of the foot of the wearer, and the at least one base portion includes a lateral foot-side base portion disposed in the lateral foot-side region.
 4. The sole according to claim 2, wherein a lower surface of the toe base portion protrudes downward from the reference surface.
 5. The sole according to claim 3, wherein a lower surface of the toe base portion and a lower surface of the lateral foot-side base portion are formed to be flush with the reference surface.
 6. The sole according to claim 1, wherein the at least one pin retaining member is capable of detachably retaining the spike pin.
 7. A shoe comprising: the sole according to claim 1; and an upper connected to the sole and forming, together with the sole, a space in which the foot of the wearer is received. 